Recent content by DLH112

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    Thoughts/Questions about GR and dark matter

    I know light behaves oddly compared to normal matter, I haven't really delved into the math of GR, and that's why I'm here to ask these questions. 1) If all of our observations of the universe are based on light, what determines that the speed of light is the maximum velocity? I'm sure its...
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    Calculating the Initial Height of a Hailstone for Complete Melting on Impact

    its an online homework thing. it said that answer is wrong
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    Calculating the Initial Height of a Hailstone for Complete Melting on Impact

    ah i see. something like mgh = mL and the mass cancels so gh = L or h = L/9.8 edit: 9.8 m/s2 h = 330000 J/kg h = 330000/9.8 h = 3367.46939 m or 3.367469 km? this is wrong though... maybe i got some units wrong?
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    Calculating the Initial Height of a Hailstone for Complete Melting on Impact

    Homework Statement Assume that a hailstone at 0◦C falls through air at a uniform temperature of 0◦C and lands on a sidewalk also at this temperature. From what initial height must the hailstone fall in order to entirely melt on impact? The acceleration due to gravity is 9.8 m/sec2 and the...
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    What is the Tension in the String Holding a Submerged Cork?

    that makes sense... so it would be like (0.03)^3 then i guess
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    What is the Tension in the String Holding a Submerged Cork?

    Homework Statement A cork is held at the bottom of a bucket of water by a piece of string. The actual depth of the cork is 0.713786 m below the surface of the water. If the density of the cork is 157 kg/m3 and the volume of the cork is 3 cm3 , then what is the tension in the string...
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    What Is the Velocity of a Mass on a Spring When Displacement Is 3.6 cm?

    ah thank you. i was accidentally using 28.6 instead of 26.8.
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    What Is the Velocity of a Mass on a Spring When Displacement Is 3.6 cm?

    Homework Statement This is a 3 part problem and I've successfully solved the first 2 parts, but I don't know what I did wrong in the third part. 1) mass of 346 g on a spring with constant 26.8 N/m on a horizontal + frictionless surface. Amplitude is 6.7 cm. In part 1 i found the total...
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    How Do You Find the Center of Mass for a Non-Uniform Bar Using Calculus?

    Homework Statement find the mass of an unevenly distributed bar with length 2 meters whos mass at a point is given by an equation 0.6 + x^2. Then find the center of mass. Homework Equations The Attempt at a Solution I got the first part (finding the mass) correctly, but I can't...
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    How Does a Man's Movement Affect the Angular Speed of a Merry-Go-Round?

    so if L= Iw and I = 1/2 MR^2 then you get L = (0.5) (131) (1.4) (0.7539822). but wouldn't w need to go to infinite if R is 0?
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    How Does a Man's Movement Affect the Angular Speed of a Merry-Go-Round?

    Homework Statement A merry-go-round rotates at the rate of 0.12 rev/s with an 86 kg man standing at a point 1.4 m from the axis of rotation. What is the new angular speed when the man walks to a point 0 m from the center? Consider the merry-go-round is a solid 45 kg cylinder of...
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    Calculating Work Done by Friction

    I must've been tired and mixed up the 16.6 kg and 26 degrees, so i used 26.6 degrees when calculating instead. i feel dumb xD
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    Calculating Work Done by Friction

    sure. mg = (9.8)(16.6)= -162.68 N Fy = 161 sin(26.6) = 72.08921314 N so Fnet down/ -Fn = -90.59078686 N then W(fric) = (39.1)(0.181)(90.59078686) = -641.1200577 J
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    Calculating Work Done by Friction

    Homework Statement There's a mass (16.6 kg) on a surface with kinetic coeficient of friction 0.181. it's being pulled by a constant force of 161 N at 26 degrees above the horizontal. The block is displaced 39.1 meters. Calculate the work done by friction.Homework Equations Friction = (mu)Fn...
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